A moving magnetic field generating apparatus includes a magnet array including magnets disposed at a first pitch such that N and S poles of adjacent magnets in the magnet array are alternated, and first and second magnetic pole piece arrays extending along the magnet array to interpose the magnet array therebetween with a gap from the magnet array. The first and second magnetic pole piece arrays are disposed with a predetermined phase difference therebetween. The first magnetic pole piece array includes first magnetic pole pieces disposed at a second pitch in an array and each having a length enough to face at least two adjacent magnets in the magnet array. The second magnetic pole piece array is configured similarly to the first magnetic pole piece array. One of the first and second magnetic pole piece arrays and the magnet array is relatively moved to the other at a predetermined speed.